<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar class="page-nav-bar" @click-left="onClickLeft" left-arrow title="黑马头条"></van-nav-bar>

    <div class="main-wrap">
      <!-- 加载中 -->
      <div v-if="loading" class="loading-wrap">
        <van-loading color="#3296fa" vertical>加载中</van-loading>
      </div>
    
      <!-- 加载完成-文章详情 -->
      <div v-else-if="article.title" class="article-detail">
        <!-- 文章标题 -->
        <h1 class="article-title">{{ article.title }}</h1>
    
        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="article.aut_photo"
          />
          <div slot="title" class="user-name">{{ article.aut_name }}</div>
          <div slot="label" class="publish-date">{{ article.pubdate | relativeTime }}</div>
          <!-- 
             模板中的 $event 是事件参数
             当我们传递给子组件的数据即要使用还要修改
               传递：props
               修改：自定义事件
             简写方式：在组件上使用 v-model
               value="article.is_followed"
               @input="article.is_followed = $event"
           
             如果需要修改 v-model 的规则名称，可以通过子组件的 model 属性
           -->
          <follow-user 
             class="follow-btn" 
             v-model="article.is_followed" 
             :user-id="article.aut_id" 
          />
          <!-- <van-button
            v-if="article.is_followed"
            class="follow-btn"
            round
            size="small"
            :loading="followLoading"
            @click="onFollow"
          >已关注</van-button>
          
          <van-button
            v-else
            class="follow-btn"
            type="info"
            color="#3296fa"
            round
            size="small"
            icon="plus"
            :loading="followLoading"
            @click="onFollow"
          >关注</van-button> -->
         
        </van-cell>

          <!-- 文章内容 -->
          <div
            ref="article-content"
            class="article-content markdowm-body"
            v-html="article.content"
          ></div>
          <van-divider>正文结束</van-divider>
          <comment-list :source="article.art_id" 
          @onload-success="totalCommentCount = $event.total_count" />
        </div>
      
        <!-- 加载失败：404 -->
        <div v-else-if="errStatus === 404" class="error-wrap">
          <van-icon name="failure" />
          <p class="text">该资源不存在或已删除！</p>
        </div>
      
        <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
        <div v-else class="error-wrap">
          <van-icon name="failure" />
          <p class="text">内容加载失败！</p>
          <van-button class="retry-btn">点击重试</van-button>
        </div>
    </div>

    <!-- 底部区域 -->
    <div class="article-bottom" v-if="article.art_id">

      
      <van-icon name="comment-o" :info="totalCommentCount" color="#777" />
      <collect-article 
      v-model="article.is_collected" 
      :article-id="article.art_id" 
      />
      <like-article 
      v-model="article.attitude" 
      :article-id="article.art_id" 
      />
      <van-icon name="share" color="#777777"></van-icon>
    </div>
  </div>
</template>

<script>
import { getArticleById } from '@/api/article.js'
import { ImagePreview } from 'vant'
import FollowUser from '@/components/follow-user'
import CollectArticle from '@/components/collect-article'
import LikeArticle from '@/components/like-article'
import CommentList from './comment-list.vue'

ImagePreview(['https://img01.yzcdn.cn/vant/apple-1.jpg']);

export default {
  name: 'ArticleIndex',
  components: {
    FollowUser,CollectArticle,LikeArticle,CommentList
  },
  props: {
    articleId: {
      type: [Number, String, Object],
      required: true
    }
  },
  created () {
    this.loadArticle()
    this.onLoad()
  },
  data () {
    return {
      article: {}, // 文章详情
      loading: true, // 加载中的 loading
      errStatus: 0, // 失败的状态码
      followLoading:false, // loading 状态显示与否
      totalCommentCount: 0
    }
  },
  methods: {
    async loadArticle () {
      this.loading = true
      try {
        const { data } = await getArticleById(this.articleId)
        this.article = data.data

        setTimeout(()=>{
          this.previewImage()
        },0)
      } catch (err) {
        if(err.response && err.response.status === 404){
          this.errStatus = 404
        }
      }
       // 无论成功还是失败，都需要关闭 loading
      this.loading = false
    },
    onClickLeft() {
      this.$router.back()
    },
    previewImage(){
      const articleContent =this.$refs['article-content']
      const imgs = articleContent.querySelectorAll('img')
      const images = []

      imgs.forEach((item, index) => {
        images.push(item.src)

        item.onclick = () => {
          ImagePreview({
            images: images,
            startPosition: index
          })
        }
      })
    },
    
  },
}
</script>

<style scoped lang="less">
@import './github-markdown.css';
.article-container {
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    /deep/.van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>